Mr. Tate on Basaltic Rocks. 205 



After leaving Cullernose, the basalt forms the craggy hill 

 of Hipsheugh, and it ranges on to Howick Hall and through 

 the Howick parks to Little Mill, where it has been quarried, 

 and an interesting section is exposed. The basalt is 30 feet 

 in thickness ; but abutting against its perpendicular w r estern 

 side, are highly inclined beds of limestones and shales ; the 

 limestone is unaltered, but the shales are shattered and bent 

 over near the basalt, the dip being S.W. from 80° to 40°, as 

 shown in Section 8 : — 



In another part of the same quarry, small veins of basalt 

 penetrate the limestone, which rests on the basalt, the two 

 rocks being completely welded together so as to form one 

 mass. In section 9, (b) is columnar basalt ; (I) three layers 

 of limestone, from 4 to 8 inches thick ; and (b) veins of basalt 

 1 to 2 inches in thickness. 



Near to Howick Pasture House the basalt is covered by a 

 shale much metamorphosed, over which are a blue limestone 

 and another bed of shale. It forms a high craggy hill at 

 Howick Heugh ; and ranges in a broad belt a little eastward 

 of Littlehoughton, and crossing the northern part of Long- 

 houghton, it thence goes by Peppermoor and Harlow Hill to 

 Ratcheugh Crag. At Peppermoor there are indications of 

 two intrusions ; in one part granular limestone lies above the 

 basalt, and not far from this the covering is an indurated 

 sandstone ; but the sections at Ratcheugh and Snab Leazes 

 are among the most interesting in the whole range. 



At Ratcheugh Crag, which is four hundred feet above the 

 sea-level, the basalt rises from a steep talus of fallen rock, in 

 grand columns, to the height of about eighty feet, with a cliff 

 face to the west ; and above it are beds of limestone, sixteen 

 feet in thickness, peculiarly metamorphosed ; for while the 

 bed immediately above the basalt is, in some parts, but 

 slightly altered, the next beds are highly crystalline ; they 

 dip with the basalt S. E. 15°, and are on the slope of the hill 

 eastward, covered by a fossiliferous shale. About five 

 hundred yards southward is another basaltic cliff at Snab 

 Leazes, where the rock, which is sixty-three feet high, is 

 quarried for a road-stone, the top of this cliff being one 

 hundred feet lower in level than the summit of Ratcheugh 

 Crag. For some distance between these basaltic cliffs the 

 section is obscured ; but by means of the fossiliferous shale, 

 overlying the limestone covering Ratcheugh Crag, we are 

 enabled to connect the whole, for this shale is traceable 



